1. Field of the Invention
This invention relates to control means for a film drive mechanism for a photographic camera, and more particularly to a film drive control means for a camera which is loaded with a 110 type film cartridge.
2. Description of the Prior Art
It is well known in the art to provide a film drive means in a photographic camera for automatically winding up a film in the camera. It is recently desired that the film drive means be incorporated in cameras which are loaded with a 110 type film cartridge. In order to effect an automatic film drive in a camera loaded with an ordinary 35m/m type film magazine, the drive motor in the camera is started by an exposure completion signal and stopped by a one frame feed completion signal. In the camera loaded with a 110 type film cartridge, the motor is stopped by a signal from a senser which engages with a perforation of the film when the film is fed by one frame.
In the camera loaded with the 110 type film cartridge, there is a problem when an automatic film drive means is incorporated. In the 110 type film cartridge, the film retained therein is fed from a film feed-out chamber to a film take-up chamber by way of a film exposure aperture. The film is not secured to a part of the film feed-out chamber and accordingly is completely fed out of the film feed-out chamber and is taken up into the film take-up chamber. However, if the film is completely wound up into the film take-up chamber, the film must be taken out of the film take-up chamber. This is a very troublesome task and one which lowers the working efficiency in a film processing laboratory. Therefore, it is desired that a part of the trailing end of the film remains in the take-up chamber aperture rather than being completely taken up into the film take-up chamber. For the purpose of ensuring the incomplete taking up of the film in the 110 type film cartridge, the film is provided near the trailing end thereof with a film stopping elongated perforation and the film take-up chamber is provided on the inner surface thereof with a film stopper which engages with this elongated perforation of the film when the trailing end of the film approaches the film take-up chamber. In operation, when the film is wound up manually, the user of the camera knows when the film is stopped by the engagement of the perforation and the stopper since the user senses an extraordinarily increased load when attempting to continue winding the film. If the film is automatically wound up by a motor drive means, however, the film will break when the film is forcibly wound up after the elongated perforation has engaged with the stopper or the drive motor will overheat.